Bio-fuel Production From Carbondioxide Gas Using S. elongatus PCC 7942 from Cyanobacteria

The scope of this study, is  1-butanol production from CO2 with S. elongatus PCC 7942 culture. The yields of 1-butanolproduced/CO2utilized have been calculated. The maximum concentration of produced 1- butanol is 35.37 mg/L and 1-butanolproduced/CO2utilized efficiency is 92.4. The optimum operational conditions were  30°C temperature, 60 W intensity of light, pH= 7.1, 120 mV redox potential, 0.083 m3/sn flow rate with CO2 and 0.5 mg/l dissolved O2 concentration. Among the enzymes on the metabolic trail of the production of 1-butanol via using S. elongatus PCC 7942 cyanobacteria. At maximum yield; the measured concentrations are 0.016 µg/ml for hbd; 0.0022 µg/ml for Ter and 0.0048 µg/ml for AdhE2. The cost analyses necessary for 1-butanol production has been done and the cost of 1 litre 1-butanol has been determined as maximum 1.31 TL/L

Treatability of streptomycin in sequential anaerobic baffled reactor (ABR) and toxicity removal

Bu çalışmada streptomisin antibiyotiğinin arıtılabilirliği anaerobik perdeli reaktör (APR) ve onu takip eden aerobik sürekli karıştırmalı tank reaktör (SKTR) sistemi kullanılarak araştırılmıştır. Anaerobik perdeli reaktör (APR) girişinde glikozdan gelen 3000mg/L KOİ ye ek olarak 200 mg/L streptomisin kaynaklı 131.38 mg/L KOİ ile ortalama 3000–3500 mg/L KOİ bulunmaktadır. Çalışmada azalan hidrolik bekleme sürelerinde (HBS) (38.4-19.2-12.8-9.60-7.68 gün) ve artan organik yükleme hızlarında (0.085-0.180-0.260-0.341-0.426 kgKOİ/Lgün) reaktöre verilen (200mg/L) sabit konsantrasyonda streptomisin antibiyotiğinin KOİ, streptomisin giderim verimleri ve APR’ de gaz üretim miktarları üzerine etkisi incelenmiştir. Ayrıca 200 mg/L sabit streptomisin konsantrasyonunda APR’ nin bölmelerinde ve çıkışında toplam uçucu yağ asidi (TUYA) değişimleri de incelenmiştir. KOİ giderim verimleri APR’de 19.2 günlük HBS sinde  %85’lerde tespit edilmiş olup, APR’ de streptomisin giderim verimi 12.8 günlük HBS sinde %66 olarak bulunmuştur. Ardışık anaerobik/aerobik reaktör sisteminde ise 19.2 günlük HBS sinde yaklaşık %95 KOİ ve 12.8 günlük HBS’sinde %74 streptomisin giderim verimleri elde edilmiştir. APR’de 9,60 günlük HBS inde üretilen toplam gaz ve metan gazı miktarı streptomisin için sırasıyla maksimum 504 L/gün ve 446.4 L/gün olarak bulunmuştur. Metan gaz içeriği ise %58 olarak bulunmuştur. Anaerobik reaktörde azalan HBS lerinde antibiyotik için toplam uçucu yağ asit (TUYA) konsantrasyonunun ise sıfır ya da sıfıra yakın olduğu bulunmuştur. APR/SKTR ardışık sisteminde azalan HBS lerinde Daphnia magna ile akut toksisite çalışması yapılmıştır. APR giriş, APR çıkış ve SKTR çıkış sularında akut toksisite testleri sonucu EC50 değerleri 38.4 günlük HBS inde streptomisin için sırasıyla 400 mg/L, 132mg/L ve 20 mg/L olarak hesaplanmıştır. Akut toksisite ardışık APR/SKTR reaktör sistemle %95 oranında giderilmiştir. Anahtar Kelimeler: Aerobik sürekli karıştırmalı tank reaktör(SKTR), anaerobik perdeli reaktör (APR), Daphnia magna (su piresi), streptomisin ve toksisite.In this study the anaerobic treatability of streptomycin was investigated in a sequential anaerobic baffled reactor (ABR)/ completely stirred tank reactor (CSTR) system. The ABR reactor was operated continuously through 83 days using glucose as primary substrate with constant streptomycin concentration of 200 mg/L. 200mg/L streptomycin gives an additional COD concentration to total COD thought continuous operation. 200 mg/l of streptomycin gave approximately a COD of 131.38 mg/L. The effects of decreasing hydraulic retention times (HRT) (38.4-19.2-12.8-9.60-7.68 days) on COD, antibiotic removal efficiencies and gas productions in anaerobic baffled (ABR) reactor were investigated at constant streptomycin concentration of 200mg/L. Moreover, the effects of decreasing HRT on the change of, volatile fatty acid (VFA) accumulation were investigated in the effluent and in the compartments of ABR reactor. In this study, to toxic effect of streptomycin concentration on methane Archaea was investigated using anaerobic toxicity (ATA) test under batch conditions in the beginning of the study in order to determine in the IC50 (the streptomycin concentration which caused 50% decreases in the methanogenic activity) value of the streptomycin. The IC50 value for streptomycin was found as 292.06 mg/L. In the continuous operation of APR reactor, for maximum COD efficiency (E=90%) and methane percentage(58%) the optimum streptomycin concentration and streptomycin loading rate were found as 200 mg/L and 0.180 kg/Lday, respectively. The total COD removal efficiencies changed between 81% and %95 at different HRTs (38.4-19.2-12.8-9.60-7.68 days) in anaerobic/aerobic reactor system. The maximum COD removal efficiencies at constant streptomycin (200mg/L) concentration were obtained as 89% and 95% in the ABR and CSTR reactor effluents at a HRT of 19.2 days. Maximum total gas, methane gas productions and methane percentage were found as 504 l/day, 446.4 l/day and 58% , respectively at a  HRT of 9.60 days. Before a HRT of 9.60 days, the daily total gas, ethane gas productions and methane percentage decreased through HRT. Maximum total gas, methane gas productions and methane percentage were found as 504 L/day, 446.4 L/day and 58%, respectively, at a HRT of 9.60 days. 259.2 L/day total gas, 187 L/day methane gas and 42% methane percentage were obtained at a HRT as long as 38.4 days. This indicated the inhibition effect of HRT on methane Archeae. In the continuous operation of APR reactor, for the total volatile fatty acids (TVFA) values in the effluent of the ABR reactor were found as zero when the HRTs decreased from 38.4 days to 7.68 days. TVFA concentration was higher in the first compartment that other compartments in ABR. TFVA concentration decreased from 608 mg/l to 26 mg/L in the first compartment when the HRT decreased from 38.4 days to 19.2 days. The effluent TVFA concentrations were approximately zero at all HRTs. Bic.Alk. concentrations were lower in the first compartment than that the others compartments. This indicates the utilization of alkalinity to buffer the (TVFA) and CO2 produced from the anaerobic co-metabolism of streptomycin and COD. In anaerobic reactor system  the TVFA/Bic.Alk. ratio gives necessary information to determine the stability of the anaerobic reactor. If the TVFA/Bic.Alk. ratio is lower than 0.4, the reactor is stable (Behling et al., 1997). The TVFA/Bic.Alk. ratio varied between 0.099 and 0.005 in effluent as the HRTs were decreased from 38.4 days to 7.68 days. The antibiotic removal efficiencies at constant streptomycin (200mg/L) concentration were obtained as 66% and 74% in the ABR and CSTR reactor effluents at a HRT of 12.8 days.The total maximum streptomycin removal efficiency was 74% in the sequential reactor system at an influent streptomycine concentration of 179.57 mg/L at a HRT of 12.8 days. In this study it was found that the ?streptomycin? antibiotic was mainly degraded (59.79 mg/L) in anaerobic ABR reactor while the remaining part of this antibiotic (47.54 mg/L) was removed in the aerobic CSTR reactor. In this study, to acute toxic effect of synthetic wastewater containing streptomycin was investigated, separately, through anaerobic/aerobic degradation at decreased HRTs (38.4-19.2-12.8-9.60-7.68 days) using Daphnia magna test. The acute toxicity test results performed with Daphnia magna showed that the EC50 values decreased from influent 400 mg/L to 132 mg/L, and to 20 mg/L in the effluents of ABR and aerobic reactor at a HRT of 38.4 days. The total acute toxicity reduction in sequential ABR CSTR reactor effluent was 95%. Keywords: Aerobic continuous stirred tank reactor system (CSTR), anaerobic baffled reactor (ABR), daphnia magna, streptomycin, toxicity

FACTORS AFFECTING THE BIODEGRADATION EFFICIENCY OF SOLID WASTES: “COMPACTION AND SHREDDING OF SOLID WASTESâ€

Bu çalışmada anaerobik simüle biyoreaktörlerde katı atıkların sıkıştırılması ve parçalanmasının katı atık arıtımına ve sızıntı suyu özelliklerine etkileri üç adet biyoreaktörde incelenmiştir. Tüm reaktörler sızıntı suyu geri devirli çalıştırılmıştır. Reaktörlerden birine ham atık (kontrol reaktör), ikincisine 0.5-1cm boyutlarında parçalanmış atık (parçalamalı reaktör), üçüncüsüne ise sıkıştırılmış katı atık (sıkıştırılmış reaktör) yüklenmiştir. Tüm reaktörlerde sızıntı suyu geri devir oranı 300 ml/gün'dür. pH, kimyasal oksijen ihtiyacı (KOİ), uçucu yağ asidi (UYA), amonyum azotu (NH4-N), toplam ve metan gazı üretimleri düzenli olarak izlenmiştir. 57 günlük inkübasyon süresi sonunda pH, KOİ, UYA, BOİ5/KOİ oranları açısından parçalamalı reaktörün diğer reaktörlerden daha iyi olduğu gözlenmiştir. Kontrol, sıkıştırmalı ve parçalamalı reaktörlerden elde edilen sızıntı sularında 57 günlük anaerobik inkübasyon sonucu gözlenen KOİ değerleri sırası ile 6400 mg/l, 7700 mg/l ve 2300 mg/l, UYA değerleri ise 2750 mg/l, 3000 mg/l ve 354 mg/l'dir. pH değerleri sırası ise sırası ile 6.88, 6.76, 7.25 tir. 57 günlük inkübasyon süresi sonunda kontrol, sıkıştırmalı ve parçalamalı reaktördeki metan yüzdeleri, % 36, % 46 ve % 60'tır. BOİ5/KOİ oranı 0.44 olan parçalamalı reaktör diğer iki reaktörden daha yüksek ayrışma hızına sahiptir. Yapılan deneyler parçalamalı reaktörlerin atık miktarı, organik madde azalması ile atık ayrışma zamanı açısından diğer iki reaktöre kıyasla daha iyi olduğu gözlenmiştir. In this study, the effects of shredding and waste compaction on the anaerobic treatment of domestic solid waste and leachate characteristics was investigated in three simulated landfill anaerobic bioreactors. All of the reactors were operated with leachate recirculation. One of them was loaded with raw waste (control reactor); the second reactor was loaded with shredded waste having a diameter of 0.5-1cm (shredded reactor); the third reactor was loaded with compacted waste (compacted reactor). The leachate recirculation rate was 300 ml/day in all of the reactors. pH, chemical oxygen demand (COD), volatile fatty acids (VFA), ammonium nitrogen (NH4-N) concentrations; total and methane gas productions in the leachate samples were regularly monitored. After 57 days of anaerobic incubation, it was observed that the pH, COD, VFA concentrations, and BOD5 /COD ratio in the leachate of shredded reactor were better than the control and compacted reactor. The COD values were measured as 6400, 7700 and 2300 mg/l while the VFA concentrations were 2750, 3000 and 354 mg/l, respectively, in the leachate samples of the control, compacted and shredded reactor after 57 days of anaerobic incubation. The values of pH were 6.88, 6.76 and 7.25, respectively, after anaerobic incubation, respectively in the aforementioned reactors. It was observed that the waste shredding increased the methane percentage in the anaerobic simulated reactor. Methane percentage of the control, compaction and shredded reactors were 36 %, 46 % and 60 %, respectively, after 57 days of incubation. A BOI5/COD ratio of 0.44 was achieved in the shredded reactor indicated the better MSW stabilization resulting in a high rate than that of compacted and control reactors. It was observed that waste shredding reduced the waste quantity, the organic content of the solid waste and the biodegradation time

Treatability of nitrobenzene in sequential anaerobic (AMBR)/aerobic (CSTR) reactor system and biodegradation of nitrobenzen

Bu çalışmada nitrobenzen (NB)'in arıtılabilirliği anaerobik hareketli yatak reaktör (AHYR) ve onu takip eden aerobik sürekli karıştırmalı tank reaktör (SKTR) sistemi kullanılarak araştırılmıştır. AHYR reaktör 20 mg/L den 400 mg/L'ye artırılan NB konsantrasyonlarında (1.93 g/m3.gün'den 38.54 g/m3.gün'e arttırılan NB yükleme hızlarında) birincil substrat olarak glikoz kullanılarak 128 gün boyunca 10.38 günlük sabit hidrolik bekleme süresinde (HBS) sürekli olarak işletilmiştir. Sürekli işletim boyunca giriş KOİ konsantrasyonu 3000 mg/L glikoz-KOİ'sine eşdeğerdir. Fakat NB'nin ortama KOİ vermesi nedeniyle, NB konsantrasyonu 20 mg/L den 400 mg/L' ye arttığı zaman, giriş KOİ konsantrasyonu 3000 mg/L den 3400 mg/L'ye artmıştır. Çalışmada maksimum KOİ ve NB uzaklaştırma verimi veren optimum NB konsantrasyonu ve NB yükleme hızı, 60 mg/L ve 3.85 g NB /m3.gün olarak bulunmuştur. Optimum NB konsantrasyonu ve yükleme hızında KOİ uzaklaştırma verimi % 93 ve NB uzaklaştırma verimi ise 100% dür. Maksimum toplam gaz, metan gaz üretimi ve % metan miktarı 5.78 g/m3.gün'lük NB yükleme hızında sırasıyla 2.8 L/gün, 1.3 L/gün ve %44 olarak bulunmuştur. AHYR reaktörde toplam uçucu yağ asidi (TUYA) konsantrasyonu ilk bölmede diğer bölmelerden daha yüksek bulunmuştur. İlk bölmede NB yükleme hızı 1.93 g/m3.gün'den 38.54 g/m3.gün'e arttırıldığı zaman TUYA konsantrasyonu AHYR'nin ilk bölmesinde 46 mg/L'den 160 mg/L'ye artmıştır. Optimum ve maksimum NB yükleme hızlarında TUYA konsantrasyonları çıkışta sırasıyla 0 mg/L ve 17 mg/L olarak bulunmuştur. AHYR’ nin bölmelerinde ve çıkışında TUYA/ bikarbonat alkalinitesi (Bik.Alk.) oranları ise tüm NB yükleme hızlarında 0.04'ün altındadır. Anaerobik (AHYR)/aerobik (SKTR) reaktör sisteminde toplam KOİ uzaklaştırma verimleri artan NB yükleme hızlarına bağlı olarak % 93 ile % 97 arasında değişmiş ve NB uzaklaştırma verimi ise tüm NB yükleme hızlarında %100 olarak bulunmuştur. NB anaerobik şartlar altında aniline, anilin ise aerobik şartlar altında kateşole dönüşmüştür. Anahtar Kelimeler: Anaerobik hareketli yatak reaktör, nitrobenzen, anilin, ardışık reaktör sistem. In this study the treatability of nitrobenzene(NB) was investigated in sequential anaerobic migrating blanket reactor (AMBR)/completely stirred tank reactor (CSTR) system. The AMBR reactor was operated continuously through 128 days using glucose as primary substrate with increasing NB concentrations from 20 to 400 mg/L. The NB loading rates increasing from 1.93 g/m3.day to 38.54 g.m-3.day-1 at constant hydraulic retention time (HRT) of 10.38 days. The influent COD concentrations and COD loading rate were kept constant at approximately 3000 mg/L and 0.289 g/L.day with addition of glucose through continuously operation, respectively. But, when NB concentration increased from 20 mg/L to 400 mg/L, the influent COD concentration increased from 3000 mg/L to 3400 mg/L due to NB giving an additive COD. In batch study, NB concentration caused 50% decreases in the methanogenic activity (decrease of methane gas production) were calculated as IC50 value. The IC50 value for NB were found as 109 mg/L. In continuous study, optimum NB concentration and NB loading rate were found as 60 mg/L and 3.85 g/m3.day, respectively, which given maximum COD and NB removal efficiency. COD removal efficiency remained approximately between 93 and 94 % until a NB loading rate of 5.78 g/m3day correspond to a NB concentration of 60 mg/L. NB removal efficiency was found as 100 % at all NB loading rates. The effluent NB concentrations were approximately 0 mg/L at all NB loading rates. 100 % of the nitrobenzene was reduced to aniline in the anaerobic reactor at a HRT of 10.38 days. COD and NB removal efficiencies were 93% and 100% at optimum NB concentration and NB loading rate. Maximum total gas, methane gas productions and methane percentage were found as 2.8 L/day, 1.3 L/day and %44, respectively at a NB loading rate of 5.78 g/m3.day. After a NB loading rate of 5.78 g/m3day, the daily total gas, methane gas productions and methane gas percentage decreased through NB loading rate. 1.8 L/day total gas, 0.78 L/day methane gas and 39% methane percentage  were obtained at a maximum NB loading rate of 38.54 g/m3day. This indicated the inhibition effect of NB on methane Archeae at NB loading rates as high as 38.54 g/m3day correspond to NB concentration of 400 mg/L. pH values in the effluent and in the compartments of AMBR varied between 7.0-7.9. These values were between optimum pH values. The pH values were lower in initial compartment than that the other compartments due to high total volatile fatty acids (TVFA) in the first compartment. TVFA concentration was higher in the first compartment that other compartments in AMBR. TVFA concentration increased from 46 mg/L to 160 mg/L in the first compartment when NB loading rate increased from 1.93 to 38.54 g/m3.day. The effluent TVFA concentrations were 0 mg/L and 17 mg/L, respectively at optimum 3.85 g/m3.day and maximum 38.54 g.m-3.day-1NB loading rates. Bic.Alk. concentrations were lower in the first compartment than the others compartments due to low pH. This indicates the utilization of alkalinity to buffer the TVFA and CO2 produced from the anaerobic co-metabolism of NB. TVFA/Bicarbonat alkalinity (Bic.Alk.) ratios were below 0.04 in compartments and in the effluent of AMBR at all NB loading rates. Nitrobenzene was reduced to aniline, in the first step, under anaerobic condition, and then in the second step, aniline was mineralized to catechol under aerobic conditions. The presence of aniline peak in effluent of anaerobic AMBR indicated that the nitrobenzene converted to aniline under anaerobic conditions. Aniline was biodegraded in aerobic stage. No peak of aniline was observed in the effluent of aerobic CSTR reactor. This showed that aniline was biodegraded to catechol in aerobic stage. The total COD removal efficiencies changed between 93% and 97% at increased NB loading rates in anaerobic/aerobic reactor system. NB removal efficiencies were 100% at all NB loading rates in anaerobic/aerobic sequential reactor system.  Keywords: Anaerobic migrating blanket reactor, nitrobenzene, aniline, sequential reactor system. 

THE INVESTIGATION OF ANAEROBIC TREATABILITY OF INDIGO DYES

Bu çalışma indigo boyar maddelerini kullanan tekstil endüstrisi atıksularının anaerobik arıtımına ışık tutmak amacı ile yapılmıştır. Anaerobik ve granül çamur kültürlerinde indigo boyasının anaerobik olarak biyolojik parçalanabilirliği ve bu boyanın bu kültürlerde toksisitesi araştırılmıştır. Granül ve anaerobik çamur kültürleri için toksisiteyi gösteren IC50 değerleri sırasıyla 1070 mg/L ve 510 mg/L bulunmuştur. Bu değerler granül çamur kültürünün indigo boyasının toksisitesine daha dirençli olduğunu göstermektedir. Aklimasyon çalışmalarında her iki kültürün de 30, 60 ve 100 mg/L boya derişimlerinde 13 ve 20 günlük inkübasyonları yapılmış % 100 renk giderimi ile maksimum % 45 KOİ giderme verimi gözlenmiştir. Aynı konsantrasyon aralıkları için 50 günlük inkübasyon sonunda % 70 civarında KOİ giderimleri elde edilmiştir. Kinetik çalışmalardan her iki kültür için kinetik katsayılar; maksimum substrat giderim hızı (Rmax), yarı doygunluk substrat derişimi (Ks) ve maksimum substrat giderim hız sabiti (kmax) değerleri hesaplanmıştır. Her iki kültürde Ks'lerin başlangıç KOİ'sine kıyasla düşük çıkması ortamda substrat/boya akümülasyonunun olmadığını göstermiştir. This study was performed to examine the anaerobic treatability of textile wastewaters containing indigo dyestuffs. The anaerobic biodegradability and toxicity of indigo dyestuffs were investigated in anaerobic and granular sludge cultures. IC50 values, which represent the inhibitory concentration(as 50 %) were found to be 1070 mg/L and 510 mg/L for granular and anaerobic sludge cultures, respectively. These values showed that the granular sludge culture is more resistant to toxicity of indigo dye. Acclimation studies were carried out in both two cultures at 30, 60 and 100 mg/L of indigo concentrations. %100 colour and 45% maximum COD removal efficiencies were observed at 13 and 20 days sludge incubation period Nearly 70% COD removal efficiencies were obtained at 50 days sludge incubation period for both dye concentrations. Kinetic coefficients such as maximum substrate removal rate(Rmax), half-saturation concentration of substrate(Ks) and maximum substrate removal constant(kmax) were calculated for both cultures. Obtained lower Ks values showed that the accumulation of substrate/dye not occurred

Evaluation of aquatic toxicity in wastewater of a dye-producing factory in Turkey

This study investigated the acute toxicity of chemical dye production industry wastewaters by traditional and enrichment toxicity tests, and emphasized the importance of toxicity tests in wastewater discharge regulations. The enrichment toxicity tests are novel applications indicating whether there are potential toxicity or stimulation conditions. Different organisms were used including bacteria (floc and coliform bacteria), algae (Chlorella sp.), protozoans (Vorticella sp.) and fish (Lepistes sp.), to represent four trophic levels. The toxicity test results were compared with chemical analyses to identify the pollutants responsible for the toxicity in the effluent wastewater samples. In four cases, toxicity of the effluents could not be explained by using physicochemical analyses. The results clearly showed that the use of bioassay tests produce additional information about the toxicity potential of industrial discharges and effluents